"It's not enough. It's a slap in the face," said Delores Nettles. "He'll still be a young man in his 30s when he gets out. Islan is gone forever."

James Dixon, 25, of Clinton Hill, pleaded guilty to first-degree manslaughter in the Aug. 17, 2013 beating death of Nettles.

After encountering Nettles and a group of her friends on the sidewalk, Dixon, in his confession to police, said he flirted with Nettles before discovering she was a transgender woman. After a friend ridiculed him, Dixon says he became angry and hit Nettles, causing her to strike her head on the sidewalk and then struck her again as she lay on the ground.

Prosecutors say Dixon repeatedly struck Nettles as she lay on the ground and rammed the side of her head into the sidewalk, using the ground as a "dangerous instrument." Delores Nettles removed her daughter from life support at Harlem Hospital three days after the beating.

Prosecutors did not agree with the judge's 12-year sentence and called for Dixon to receive 17 years in prison.

"No amount of time is good enough, but 17 years would have been better than 12 years," said Delores Nettles who also said the case should have been tried as a hate crime.

Nettles said she plans to seek help in pushing for federal hate crime charges

"Islan was killed because of who she was and how she was dressed," Nettles said.

And while Dixon is the only one charged in the beating, he was with seven men — a group Nettles feels contributed to the crime with hateful slurs. Prosecutors believe slurs were used before and during the attack.

"I believe everyone who was there had a hand in it," Nettles said.

Both prosecutors and police believe that Nettles' status as a transgender woman played a role in the attack and that she wouldn't have been beaten had she not been transgender.

But New York state's law on hate crimes says that there must be proof that the individual attacked was "intentionally" selected "because of a belief or perception regarding the race, color, national origin, ancestry, gender, religion, religious practice, age, disability or sexual orientation of a person."

Proving that Dixon attacked Nettles "because of" her transgender status would have required prosecutors to have extremely detailed information about what was said before and during the attack, which they did not.

Federal hate crime charges also have a high bar.

Manhattan District Attorney Cyrus Vance Jr. said that "members of the transgender community are far too often the targets of violent crime," and that the resolution of the case "affirms my office’s commitment to protecting members of the LGBTQ community.”

Michael Silverman, executive director of The Transgender Legal Defense and Education Fund, praised the work of the Manhattan District Attorney's office because too often the killers of transgender women — particularly transgender women of color — "go unpunished."

The National Coalition of Anti-Violence Programs found that 20 members of the LGBTQ community were killed due to hate violence in 2014. More than half, 55 percent, were transgender women, and 50 percent of them were transgender women of color.

Islan Nettles' case is proof of a need for an expansion of the state's hate crime laws "which currently does not include transgender people. Transgender people must be protected from hate crimes like all other New Yorkers," Silverman said.

Even though the bar is high on federal hate crime charges, Delores Nettles said she needs to at least explore the possibility to bring full justice to her child.

After a slight sense of relief that the case was winding to a close, Nettles said she finds herself feeling "furious" and disappointed.

"Justice hasn't been done yet. Twelve years is a slap on wrist," Nettles said. "That means he'll be out and he can do it again to someone else's child."

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